Reducing runner blade movement in Kaplan and bulb turbines through advanced governor functions

Governors need to maintain the frequency of the grid within acceptable limits, and an adequate responsiveness allows them to react promptly to disturbances by moving the turbine actuators. In Kaplan and bulb units, there are significant differences in the physical configuration of the guidevanes and the runner blades which require attention when designing the governor control loop. Maintenance of the blade movement system is considerably harder than for the guidevanes, and the components are subjected to much higher stress compared with the guidevanes. This paper demonstrates how governors can contribute to reducing wear in the blade system.